/*
 *  Aethyra
 *  Copyright (C) 2006  The Mana World Development Team
 *
 *  This file is part of Aethyra based on original code
 *  from The Mana World.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <algorithm>
#include <cmath>

#include <guichan/color.hpp>

#include "animationparticle.h"
#include "configuration.h"
#include "imageparticle.h"
#include "log.h"
#include "map.h"
#include "particle.h"
#include "particleemitter.h"
#include "textparticle.h"

#include "resources/resourcemanager.h"

#include "utils/dtor.h"
#include "utils/fastsqrt.h"
#include "utils/xml.h"

#define SIN45 0.707106781f

class Graphics;
class Image;

int Particle::particleCount = 0;
int Particle::maxCount = 0;
int Particle::fastPhysics = 0;
int Particle::emitterSkip = 1;
const float Particle::PARTICLE_SKY = 800.0f;

Particle::Particle(Map *map):
    mAlive(true),
    mLifetimeLeft(-1),
    mLifetimePast(0),
    mFadeOut(0),
    mFadeIn(0),
    mAlpha(1.0f),
    mAutoDelete(true),
    mMap(map),
    mGravity(0.0f),
    mRandomness(0),
    mBounce(0.0f),
    mFollow(false),
    mTarget(NULL),
    mAcceleration(0.0f),
    mInvDieDistance(-1.0f),
    mMomentum(1.0f)
{
    Particle::particleCount++;
    if (mMap)
        setSpriteIterator(mMap->addSprite(this));
}

Particle::~Particle()
{
    // Remove from map sprite list
    if (mMap)
        mMap->removeSprite(mSpriteIterator);
    // Delete child emitters and child particles
    clear();
    Particle::particleCount--;
}

void Particle::setupEngine()
{
    Particle::maxCount = (int)config.getValue("particleMaxCount", 3000);
    Particle::fastPhysics = (int)config.getValue("particleFastPhysics", 0);
    Particle::emitterSkip = (int)config.getValue("particleEmitterSkip", 1) + 1;
    disableAutoDelete();
    logger->log("Particle engine set up");
}

void Particle::draw(Graphics *, int, int) const
{
}

bool Particle::update()
{
    if (!mMap)
        return false;

    if (mLifetimeLeft == 0)
        mAlive = false;

    Vector oldPos = mPos;

    if (mAlive)
    {
        //calculate particle movement
        if (mMomentum != 1.0f)
        {
            mVelocity *= mMomentum;
        }

        if (mTarget && mAcceleration != 0.0f)
        {
            Vector dist = mPos - mTarget->getPosition();
            dist.x *= SIN45;
            float invHypotenuse;

            switch (Particle::fastPhysics)
            {
                case 1:
                    invHypotenuse = fastInvSqrt(
                        dist.x * dist.x + dist.y * dist.y + dist.z * dist.z);
                    break;
                case 2:
                    invHypotenuse = 2.0f /
                        fabs(dist.x) + fabs(dist.y) + fabs(dist.z);
                    break;
                default:
                    invHypotenuse = 1.0f / sqrt(
                        dist.x * dist.x + dist.y * dist.y + dist.z * dist.z);
                    break;
            }

            if (invHypotenuse)
            {
                if (mInvDieDistance > 0.0f && invHypotenuse > mInvDieDistance)
                {
                    mAlive = false;
                }
                float accFactor = invHypotenuse * mAcceleration;
                mVelocity -= dist * accFactor;
            }
        }

        if (mRandomness > 0)
        {
            mVelocity.x += (rand()%mRandomness - rand()%mRandomness) / 1000.0f;
            mVelocity.y += (rand()%mRandomness - rand()%mRandomness) / 1000.0f;
            mVelocity.z += (rand()%mRandomness - rand()%mRandomness) / 1000.0f;
        }

        mVelocity.z -= mGravity;

        // Update position
        mPos.x += mVelocity.x;
        mPos.y += mVelocity.y * SIN45;
        mPos.z += mVelocity.z * SIN45;

        // Update other stuff
        if (mLifetimeLeft > 0)
        {
            mLifetimeLeft--;
        }
        mLifetimePast++;

        if (mPos.z > PARTICLE_SKY || mPos.z < 0.0f)
        {
            if (mBounce > 0.0f)
            {
                mPos.z *= -mBounce;
                mVelocity *= mBounce;
                mVelocity.z = -mVelocity.z;
            }
            else
            {
                mAlive = false;
            }
        }

        // Update child emitters
        if ((mLifetimePast-1)%Particle::emitterSkip == 0)
        {
            for (EmitterIterator e = mChildEmitters.begin();
                 e != mChildEmitters.end(); e++)
            {
                Particles newParticles = (*e)->createParticles(mLifetimePast);
                for (ParticleIterator p = newParticles.begin();
                     p != newParticles.end(); p++)
                {
                    (*p)->moveBy(mPos);
                    mChildParticles.push_back (*p);
                }
            }
        }
    }

    Vector change = mPos - oldPos;

    // Update child particles

    for (ParticleIterator p = mChildParticles.begin();
         p != mChildParticles.end();)
    {
        //move particle with its parent if desired
        if ((*p)->doesFollow())
        {
            (*p)->moveBy(change);
        }
        //update particle
        if ((*p)->update())
        {
            p++;
        }
        else
        {
            delete (*p);
            p = mChildParticles.erase(p);
        }
    }

    if (!mAlive && mChildParticles.empty() && mAutoDelete)
    {
        return false;
    }

    return true;
}

void Particle::moveBy(const Vector &change)
{
    mPos += change;
    for (ParticleIterator p = mChildParticles.begin();
         p != mChildParticles.end(); p++)
    {
        if ((*p)->doesFollow())
        {
            (*p)->moveBy(change);
        }
    }
}

void Particle::moveTo(float x, float y)
{
    moveTo(Vector(x, y, mPos.z));
}

Particle* Particle::addEffect(const std::string &particleEffectFile,
                              int pixelX, int pixelY, int rotation)
{
    Particle *newParticle = NULL;

    XML::Document doc(particleEffectFile);
    xmlNodePtr rootNode = doc.rootNode();

    if (!rootNode || !xmlStrEqual(rootNode->name, BAD_CAST "effect"))
    {
        logger->log("Error loading particle: %s", particleEffectFile.c_str());
        return NULL;
    }

    ResourceManager *resman = ResourceManager::getInstance();

    // Parse particles
    for_each_xml_child_node(effectChildNode, rootNode)
    {
        // We're only interested in particles
        if (!xmlStrEqual(effectChildNode->name, BAD_CAST "particle"))
            continue;

        // Determine the exact particle type
        xmlNodePtr node;

        // Animation
        if ((node = XML::findFirstChildByName(effectChildNode, "animation")))
        {
            newParticle = new AnimationParticle(mMap, node);
        }
        // Image
        else if ((node = XML::findFirstChildByName(effectChildNode, "image")))
        {
            Image *img= resman->getImage((const char*)
                    node->xmlChildrenNode->content);

            newParticle = new ImageParticle(mMap, img);
        }
        // Other
        else
        {
            newParticle = new Particle(mMap);
        }

        // Read and set the basic properties of the particle
        float offsetX = XML::getFloatProperty(effectChildNode, "position-x", 0);
        float offsetY = XML::getFloatProperty(effectChildNode, "position-y", 0);
        float offsetZ = XML::getFloatProperty(effectChildNode, "position-z", 0);
        Vector position (mPos.x + (float)pixelX + offsetX,
                         mPos.y + (float)pixelY + offsetY,
                         mPos.z + offsetZ);
        newParticle->moveTo(position);

        int lifetime = XML::getProperty(effectChildNode, "lifetime", -1);
        newParticle->setLifetime(lifetime);

        // Look for additional emitters for this particle
        for_each_xml_child_node(emitterNode, effectChildNode)
        {
            if (!xmlStrEqual(emitterNode->name, BAD_CAST "emitter"))
                continue;

            ParticleEmitter *newEmitter;
            newEmitter = new ParticleEmitter(emitterNode, newParticle, mMap,
                                             rotation);
            newParticle->addEmitter(newEmitter);
        }

        mChildParticles.push_back(newParticle);
    }

    return newParticle;
}

Particle *Particle::addTextSplashEffect(const std::string &text, int x, int y,
                                        const gcn::Color *color,
                                        gcn::Font *font, bool outline)
{
    Particle *newParticle = new TextParticle(mMap, text, color, font, outline);
    newParticle->moveTo(x, y);
    newParticle->setVelocity(((rand() % 100) - 50) / 200.0f,    // X
                             ((rand() % 100) - 50) / 200.0f,    // Y
                             ((rand() % 100) / 200.0f) + 4.0f); // Z
    newParticle->setGravity(0.1f);
    newParticle->setBounce(0.5f);
    newParticle->setLifetime(200);
    newParticle->setFadeOut(100);

    mChildParticles.push_back(newParticle);

    return newParticle;
}

Particle *Particle::addTextRiseFadeOutEffect(const std::string &text,
                                             int x, int y,
                                             const gcn::Color *color,
                                             gcn::Font *font, bool outline)
{
    Particle *newParticle = new TextParticle(mMap, text, color, font, outline);
    newParticle->moveTo(x, y);
    newParticle->setVelocity(0.0f, 0.0f, 0.5f);
    newParticle->setGravity(0.0015f);
    newParticle->setLifetime(300);
    newParticle->setFadeOut(50);
    newParticle->setFadeIn(200);

    mChildParticles.push_back(newParticle);

    return newParticle;
}

void Particle::setMap(Map *map)
{
    mMap = map;
    if (mMap)
        setSpriteIterator(mMap->addSprite(this));
}

void Particle::clear()
{
    delete_all(mChildEmitters);
    mChildEmitters.clear();

    delete_all(mChildParticles);
    mChildParticles.clear();
}